The products of sweat gland function have been periodically examined using a variety of techniques. Recent advances in stain technology permit the visualization of nanogram amounts of proteins with a photoreactive silver stain and subpicogram quantities with fluorography and rare earth screen radioautography. Data presented in this proposal indicate that reproducable polypeptide patterns can be obtained from sweat collected from normal volunteers with little variation in the most prominent components. There were no evidences of cytoskeletal proteins indicating that proteins in sweat have not leaked from lysing cells or whole cell contaminants in sweat preparations. Preliminary data obtained from sweat of patients with cystic fibrosis indicate that there are significant protein differences when compared to that of normal controls. Using the above methods, we will analyse sweat from larger numbers of normal volunteers, patients with cystic fibrosis and parents of children with cystic fibrosis to confirm the abnormal polypeptide pattern. We have identified two spots in the normal sweat polypeptide pattern as albumin and alpha-1-antitrypsin. A major goal will be the identification of other sweat components by immunoblot methods using commercially available antibodies to human serum and tissue antigens. A second goal is to complete the development of a computer-assisted method for scanning and quantitation of sweat polypeptides identified in polyacrylamide gels inorder to facilitate analysis of large numbers of electrophoretograms. Finnally, we hope to isolate a polypeptide in cystic fibrosis sweat is characteristic for the disease and which represents the abnormal gene product.